This invention relates to a cold/warm air outlet assembly for an air conditioner. The cold/warm air outlet assembly is to be mounted on a vertical part of an air conditioner duct which is arranged extending upward in a front corner part of a cab of a construction machine such as a hydraulic excavator.
In a construction machine such as a hydraulic excavator, a cab is in a closed state surrounded at four sides and a ceiling thereof with glass plates, steel plates and/or the like to permit performing construction work even in severe weather environments such as rain, strong winds and snow. In construction work under the blazing sun in midsummer, the interior of the cab in the closed state becomes considerably hot so that an operator of the construction machine is forced to work under severe conditions. Due to severe heat, the operator may suffer from dehydration in some instances. JP 8-175156 A, for example, discloses an invention on an air conditioner duct for a hydraulic excavator, which comprises three ducts extending from an air conditioner arranged on a floor behind an operator""s seat, one having a cold air outlet opening in an upper rear part of the operator""s seat, another having a cold air outlet opening near a foot area below the operator""s seat, and the remaining one having a cold air outlet opening on a forward outboard side of the operator""s seat.
The air outlet opening on the forward outboard side of the operator""s seat has a shape formed by cutting off a side wall of an air outlet member which is in an upwardly tapered, substantially conical shape. The air outlet member is turnably supported on a vertical part, which is arranged on an upstream side and extends in a vertical direction, so that the air outlet opening can be directed in a desired direction in a horizontal plane. Inside the air outlet opening which opens in a somewhat upward direction, plural fins are connected together in parallel by connecting rods. By manipulating a knob connected to the fins, the fins can be adjusted in an interlocked stepless manner into a direction ranging from an upward direction to a downward direction. As a consequence, the blowing direction of cold air can be set in any desired vertical direction.
In a construction machine, such as a hydraulic excavator, with a heavy machine mounted thereon, a glass window covering the front of a cab is arranged as wide as possible, generally extending over the entire area of the front such that construction work can be performed while fully watching and confirming the state of operation by a bucket, which is arranged on a free end portion of the heavy machine to perform loading of earth or sand, the ground, the working locations of workers, and the like. When the sun shines into the cab from the front in summer, the sunlight enters from an upper front through the front glass window and the strong sunlight impinges primarily on the chest to feet of the operator. To begin construction work under the strong sunlight in summer, the operator often presets the temperature of the air conditioner at a rather low level and its air volume at a maximum level and, when the cab has become cool subsequent to performing work for a while, resets the preset temperature and air volume to appropriate values. These values are automatically controlled in the case of an air conditioner of the type that the room temperature and air volume are automatically controlled.
According to the above-mentioned conventional technique, the direction of a cold wind blowing out of the air outlet can be set in desired vertical and horizontal directions by turning the air outlet member as desired and controlling the knob in the air outlet. If no sufficient refreshing feeling is available only with cold air from the air outlets arranged in the upper part behind the operator""s seat and near the foot area, respectively, the operator generally sets the direction of the air outlet of the air outlet member such that the air outlet is directed toward his face or chest, and then performs work. In this case, the operator""s face and chest against which cold air is directly blown are cooled to such extent that he feels sufficiently cool. However, the lower half of the operator""s body such as the femoral and pelvic regions, against which cold air does not blow directly and only a wraparound wind blows indirectly, is exposed to the impinging sunlight and is heated by radiant heat. The operator, therefore, cannot enjoy much comfort. After the temperature of the cab has dropped to such extent as the operator feels cold, the operator can feel comfortable for the first time.
As the lower half of the operator""s body, said lower half being exposed to cold air only indirectly even after the temperature in the cab has changed to a stable level, tends to feel hot, the operator has a tendency to set the cooling temperature of the air conditioner at a rather low level so that the temperature in the cab may often be lowered beyond necessity. If the operator adjusts the knob at the air outlet to direct the cold air toward the lower half of his body with a view to avoiding such a problem, the temperature of the upper half of his body, such as his face, is not lowered, thereby not only failing to obtain comfort but also possibly overcooling the abdominal region so that the operator may feel unwell. This problem is not limited to the time of working in a cooled environment in summer, but a similar situation also arises when working in a heated environment at the time of a cold weather such as winter.
When the humidity is high as in the rainy season or when the exterior temperature is low as in winter or the like, dew may be formed on the front glass window to cloud the same. To demist the front glass window, the operator may direct the air outlet member toward the front glass window to blow cold air or warm air against the front glass window. During this demisting period, cold air or warm air is blown only indirectly against the operator so that the operator cannot feel comfortable. Depending upon the convenience in proceeding with work, the operator may have to proceed with the work while consulting with workers working around the construction machine with an egress/ingress door, which is located in a side wall of the cab, kept open. In such a case, it is also necessary to direct the air outlet member toward an exit/entrance to shut off warm air or cold air which would otherwise enter through the exit/entrance. This leads to an inconvenience that a stream of air-conditioned air does not blow against the operator.
As the direction of cold or warm air blown out of the air outlet can be set in a desired direction in the conventional art, the comfort of the operator""s working environment under air conditioning can be satisfied accordingly. Nonetheless, the conventional art is not fully satisfactory in the comfort of a working environment under air conditioning especially in the hot or cold season or when air conditioning is used for a multiplicity of purposes, because cold or warm air cannot be blown in a different direction concurrently with maintaining the operator""s whole body at a comfortable temperature or blowing cold or warm air against the operator.
The present invention has been completed with a view to overcoming such inconvenience in the conventional art, and has as an object the provision of a cold/warm air outlet assembly for a construction machine, which can fully meet desires for the comfort of a working environment of an operator under air conditioning and use of air conditioning for a multiplicity of purposes.
To solve the above-described problems, the present invention is characterized in that a plurality of air outlets are arranged in a vertical direction of a casing to be mounted on a vertical part of an air conditioner duct, and directions of cold/warm air blowing out of the respective air outlets can be independently set in a vertical direction and a horizontal direction. Preferably, the casing may comprise a group of plural small casings stacked in the vertical direction such that the small casings are slidingly turnable in a horizontal direction relative to each other, and the small casings are each provided with at least one air outlet formed therethrough. A circumferential wall of the casing is constructed of a conical or upwardly tapered tubular member. A restrictor may preferably be interposed on an upstream side of one of the air outlets, the one air outlet being located on a downstream side, to control a flow rate of the cold/warm air. At least one of the air outlets may preferably be formed through an upwardly-directed, tilted wall which forms at least a part of the circumferential wall of the casing. With respect to each air outlet, plural fins may be arranged turnably about a horizontal rod, and are interlocked by a connecting member which connects the fins together.